FIG. 1 shows an exemplary prior art configuration of two semiconductor devices 102 and 103 configured with other elements to form a half bridge circuit. The devices may be MOS devices, SOI, or other type. The devices are typically manufactured using known techniques in which the various required layers are deposited on a substrate 201 as shown in FIG. 2. Devices 102 and 103 are each usually fabricated on a chip, and border 125 represents the external boundaries of the chips.
As FIG. 1 shows, one standard application includes the use of external capacitors 105 and 106 in order to measure the output of the half bridge. A sensing lead 107 is usually connected outside of the chip on which the SOI devices 102 and 103 reside. The sensing lead may be measured using standard equipment. The remainder of the external elements, inductor 108, capacitors 109 and 115 and resistor 110, are arranged to form a standard resonant output circuit.
In operation, high voltage capacitor 105 transfers AC signals to sensing lead 107 and such signals are sent to a measurement device in order to monitor operation of the SOI devices from an external piece of equipment. While the arrangement is basically satisfactory, the use of external components increases the cost and decreases the reliability.
The external monitoring is required in a variety of applications. For example, it is desirable in some switching circuits to maintain operation of the device in what is termed the soft switching region. The only way to accomplish this objective is to monitor the operation of the device and provide correction if the hard switching region is approached.
In view of the foregoing, it would be desirable to construct a sensing apparatus that does not require so many additional components. It would also be desirable to minimize manufacturing costs of such devices. It is also a desirable object to eliminate the need for an additional external capacitor.